Typewriting machine



g- 8, 1939- w. A. DOBSON 2,168,517

TYPEWRITING MACHINE Filed March 18, 1936 2 Sheets-Sheet 1 INVEN TON BY ATTORNEY. Z

Patented Aug. 8, 1939 UNITED STATES PTENT OFFEOE TYPEWRITING MACHINE Application May 18, 1936, Serial No. 80,228

12 Claims.

This invention relates to typewriting machines, more especially those of the portable class, and the aim of the invention is to minimize the noise of operation of the unversal bar mechanism which enables the keys to control the ribbon-movements, etc. It has been usual to employ a trans-- verse universal bar placed directly beneath the key-levers. The levers have a hammering action upon the universal bar which is somewhat ill-noisy owing to the frequent operation of the universal bar.

The invention is illustrated with respect to a machine of the compact type in which the keylevers have generally a U-form so as to rise in front of the body of type-action mechanism, and also up in rear of said mechanism.

According to the present improvements, the universal bar extends across the machine just in rear of the front legs of the system of keylevers.

To obtain quietness as well as accuracy, the universal bar, instead of being level, is placed at an inclination of about forty-five degrees, and every key-lever has an arm for striking down uponsaid universal bar. Said striking arm is inclined. The universal bar is swung rearwardly by the keys. Owing to the inclination of the downwardly-striking arm and the corresponding edge of the swinging universal bar, it results that 30, noise is substantially reduced. The arms on the key-levers are bendable, each one extending upwardly and rearwardly from the vertical leg of the U-portion of the key-lever. They are made bendable so that the variation in key-travel re- 35 sulting from the standard keyboard arrangement may be compensated for, and each striking arm contacts the universal bar in such manner as to insure accuracy and uniformity of operation of the said universal bar.

For further quieting the operation, the universal bar may be faced with a pad of fibrous wearing material to be struck by the bendable arms on the key-levers. If desired the universal bar might be provided with metal facings overly- 45 ing the pad so as toguard against wear while securing the advantage of a yielding contact be tween the key-lever and the universal bar.

There is also disclosed a construction in which the pad on the universal bar is curved to offer a 50 round surface to the bendable striking arm which is formed on the key-lever, and in order to prevent undue wear of the pad, the bendable striking arm is widened to give a broad contact surface to reduce wear. In this form the angle of 55 the striking arms does not need to correspond with the angle of the universal bar, because the contact occurs only along the bend or flange of the universal bar.

The universal bar is swingably mounted on studs which project inwardly from the side-plates of the machine-frame, upwardly-extending brackets of the said universal bar being pivoted to the said studs. Extending upwardly from one of said brackets is an arm to which is pivoted the front end of the pawl which extends downwardly and rearwardly to drive the ribbon-winding ratchet-wheel which is usually mounted at the bottom of the machine under the type-bars. From the other of the said brackets there extends rearwardly an arm which is connected at its rear to the mechanism which vibrates the ribbon up and down in front of the platen at the keystrokes.

It is thus a feature of this invention that the swinging motion of the universal bar, in addition to materially quieting the operation of the machine, is also utilized to operate the ribbonfeed mechanism by a directly-carried pawl; and simultaneously to operate the i'lbbon-vibrator'by a directly-carried operative connection, thus sim' plifying and lightening the structure of the chine, and effecting economies in manufacture.

Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure l is a fragmentary transverse vertical section of a typewriter of the noiseless portable class, taken through the points il on Figure 6.

Figure 2 is a modification of the universahbar construction.

Figure 3 is a further modification illustrating means for protecting the cushion of the universal bar against wear.

Figure 4 is a perspective of the cushion protection of Figure 3. 40

Figure 5 is a front elevation of the left ribbonspool showing the tripping device of the automatic ribbon-reversing mechanism.

Figure 6 is a fragmentary plan of the machine shown in Figure 1.

Figure 7 is a further modification of the universal bar shown in Figure 1.

The universal bar Ill, formed with an upwardly and rearwardly extending contact surface til and incorporating brackets H pivoted from the studs l2 secured in the side-plates I3 of the machine-frame I3 presents a novel and superior manner of actuating the ribbon-feed and ribbonvibrator. What would ordinarily be a harsh and direct impact between the key-bars l4 and universal bar I!) is converted into pivotal movement by reason of the cams or fingers !5 which are formed in the key-bars M to cooperate with the universal bar I and impart a rocking motion thereto during the key-bar stroke. The universal bar is thus free to withdraw from the impact.

The rocking motion developed is used to advantage as a means of reducing the undesirable noise caused by the ordinarily direct impact between the key-bars and the universal bar. Such noise as arises may be dampened or suppressed by the use of pads I6 of suitable buffing material attached to both the upper and lower surfaces of the universal bar II], as shown in Figures 1 and 2, or to the upper or lower surface only, as shown in Figures 3 and 7. The buffing material may be attached by any suitable means, such as cement or rivets or both.

To protect the surface of the buffing material it from the wear which would naturally result from the contact of the fingers l5, a suitable guard 11, preferably of spring steel, may be riveted or otherwise secured to the universal bar H], as illustrated by Figure 3. The forward extensions IB of guard I! overlie the cushion, and are preferably made slightly wider than the thickness of the cam-fingers I5. The intermediate spaces between the extensions i8 serve as a means of preventing the transmission of sound.

The rocking motion of the universal bar it) is additionally used as the means of operating the ribbon-vibrator and ribbon-feed mechanism in such a manner as to greatly reduce the complexity and number of parts necessary for such operation, as hereinafter explained. The vibrator mechanism, later described, is directly actuated by a bar !9. The ribbon-feed mechanism is actuated by the directly carried pawl 29.

The automatic reversal of the ribbon-spool is carried out in a manner appreciably like that shown in my United States Patent No. 1,903,505 of April 11, 1933. .with the exception that there has been a simplification of action and conserving of space.

The key-bars 14 are substantially U-shaped, and are pivoted in frame w on a universal fulcrum shaft 2 i. The key-bars are formed with the usual forward key-bearing extensions 4 The cams or fingers l5, which'overlie the universal bar l9, may be adjusted with respect to the contact surface [8 of the universal bar so as to compensate for the variation in key-travel resulting from the arrangement of keys in the standard four-bank keyboard. The fingers l are preferably made by forming slots in the keybar proper I4 so that although the correct angle corresponding to the location of a key in the keyboard (see Figure 1) may be given to the finger as the key-bar proper is being made, suitable adjustments after the key-bars are assembled in the machine may be made by simply bending the fingers, rather than by machining or filing. Modifications are shown in Figures 2 and 7 where, instead of confining the contact surface of the finger l5 to the width of the key-bar, provision has been made for the bending of a flange or shoulder l5 so as to increase the contact surface of the finger l5.

A link 22, Figure 1, connects the key-bar [4 with a bell-crank 23, suitably pivoted at 24 to a member 25 secured to the machine-frame. The rear end 26 of bell-crank 23 is pivoted to a bar 21 which at its rear end is formed with rack teeth '28, in mesh with teeth 29 formed at the hub end 38 of a type-bar 3|. The operation of a keybar 14 by the operator pulls down link 22, causing it to rotate bell-crank 23 about its pivot 24 and impart a forward motion to the bar 21 which, through the agency of the meshing teeth 28 and 29, rotates the type-bar 3i about its fulcrum 32 so as to bring the type-head 33 into printing position against the platen 34, which is carried in the usual carriage 35. The link 35 in Figure 1 indicates the connection of the type-bar 3| with a momentum-accumulator mechanism, not shown, but customary in machines of the noiseless class. The key-bar I4 is urged into its normal position by spring 3i.

As the type-bar 3i swings into printing position, a shoulder 38 formed at the hub end 30 engages and actuates the usual escapement universal bar 39 which operates the customary carriage escapement (not shown) so as to move the carriage 35 in letter-space steps on the anti-friction balls 46, 40 in the usual track 4!, 4|. The type-bar mechanism and escapement universal bar are similar to that disclosed in the United States Patent to Going, No. 1,908,140 of May 9, 1933.

At preferably the left-hand end of universal bar 5! the vertical extension 42 of bracket I I pivotaliy engages the pawl 20 at fulcrum 43. A spring-clip 44 serves to maintain the engagement, and provides a. means whereby the pawl 20 can be readily disconnected from the bracket ii if necessary. A vertical post 45, preferably padded, is suitably supported on the machineirame so as to limit the rearward movement of pawl Ail by engaging a suitable shoulder or abutment 56 on the pawl.

With every stroke of a key-bar [4, the rocking of universal bar l0 draws pawl 20 forward, rotating a ratchet 4i operatively associated with pawl 26, in step-by-step movements. Ratchet 41 is mounted on ribbon-feed shaft 48, slidably journaled at 49, 58 in the side-plates I3 of the machine-frame.

Crown gears 51, 52 are mounted at each end of shaft 48, and are suited to engage either one of two spool-shaft gears 53, 54 to cause one or the other to rotate its associated ribbon-spool shaft 55, on which the usual ribbon-spools 56 are mounted.

A suitable pawl 51, Figure 1, prevents the counter-revolution of ratchet 41 when the pawl 26 is being moved rearward on the return of the universal bar It toits normal position. A tensile spring 53 maintains the engagement of pawls 5'! and 29.

The motion of universal bar also simultaneously actuates the ribbon-vibrating mechanism 59, Figure 6. The bar I9 is formed with a forwardly and downwardly extending arm 60 at its front end, where it engages the universal-barsuspension bracket H, by means of a wrist pivot 61. The rearward end of bar I3 engages a bellcrank lever 62, being slidably secured thereto by a pivot screw $3. Lever 62 is suitably pivoted at 64 to the machine-frame. The sidewardly extending arm 65 is formed with an arcuate slot t5 through which the pivot screw 63 passes, so as to permit bar is to engage the arm 65 of the bellcrank lever at various points with respect to pivot 64, and thus impart diiferent amounts of rotation to the bell-crank lever for the same amount of motion of bar I9.

An arm 6'! also pivoted at 84 is engaged by the rearwardly extending arm 68 of the bell-crank lever bymeans of a screw 69 extending into arm 51 throughan adjustment-providing slot iii. The ribbon-vibrator 59, which is of familiar design, being that used in the well-known Underwood typewriter, is connected to the arm 5? by means of a link I! which may be placed into either of two holes 12, it so as to provide means of adjusting the vertical travel of the ribbon-vibrator 59 with respect to the motion of bell-crank lever 52.

In this manner, the rocking motion of the universal bar Ill operates the ribbon-vibrator with a minimum of operating parts.

The usual bichrome ribbon, as it, Figure 5, is divided into two colors, one placed above the other. The ribbon-vibrator must bring either color into printing position at the will of the operator. This is accomplished by regulating the vertical travel of the ribbon-vibrator.

For making such color shift, a color-lever i5 is pivoted in a frame or bracket [5 supported on the machine-frame. A forwardly and downwardly extending leg ll of lever 75 is connected to bar 59 by a suitable wire link 18 which may engage bar It in either one of two holes i9, 80, so as to provide a means of adjusting the transverse motion of bar It with respect to lever 65.

When the operator wishes to change from one color to another, lever i5 is thrown to either the extreme right or left hand position, thus shifting bar l9 so as to bring pivot screw 53 to either end of the slot 66. The same amount of rearward travel of bar l9 resulting from the universal-bar movement can therefore be made to cause a different swing of arm 5? attached to bell-crank 52, and consequently a different degree of vertical motion of ribbon-vibrator 59 so as to bring the desired color into operative position. When stenciling, in which event no action of the ribbon-vibrator is desired, an intermediate position of lever 75 will place pivot 53 of bar it before the notch 8i formed in arm 55. The full rearward motion of bar i9 is taken up by the notch 8i imparting no motion to the bell-crank 62.

Bar [9 is yieldably held in its right-hand position, shown in Figure 6, by a suitable spring 82.

The rearward motion of the universal bar in and the forward travel of the bell-crank lever 62 may be limited by the padded abutments 83 and 85 respectively. The latter is mounted on an adjustable bracket 85 so as to permit an adjustment of the universahbar movement. The movement of the key-bars it is limited by the upper and lower bumpers 56 and 5? respectively, Figure l, the bumpers being of resilient material and carried in suitable channels formed in front plate 88.

The ribbon-reversing mechanism is illustrated at Figures 5 and 6. The ribbon M, Figure 5, feeds through a slot 89 formed in the upper end of bell-crank lever 96. When the ribbon is nearly unwound from a spool, such as the left-hand spool shown in Figure 5, a button 9i formed on ribbon M near each end thereof engages the slotted portion of lever 55, said slotted portion barring the passage of the button 9i therethrough.

As the typing operation proceeds, the continued travel of the ribbon M causes lever to rotate about a fulcrum 92 suitably secured to the machine-frame, and imparts a substantially vertical movement to link 93. This mechanism is similar to that disclosed in my United States Patent No. 1,903,505, of April 11, 1933.

Link 95 is connected to a crowding lever 94, Figure 6, which is formed at its end with a pawl tooth 55, and is pivoted to the machine-frame at 95, a point below the center line of shaft 43. A ratchet 97 is mounted on the shaft immediately in front of pawl tooth 95.

The vertical motion of link 93 brings pawl 95 into engagement with any adjacent tooth of ratchet 5? at a point above the center line of shaft it. As the typing operation proceeds, the shaft 55 and ratchet 9? will continue to rotate, and the lever 94 being rotated downwardly about its pivot 55 by reason of the engagement of ratchet 97 and pawl 95 will crowd the shaft 48 to the left, bringing the left-hand gear 5| into the proximity of left-hand spool shaft gear 53 and releasing the right-hand gears 52 and 55, which had been in engagement so as to drive left-hand ribbon-spool shaft 55, Figure 6.

As it is not desirable or practicable to have the motion given to lever 94 by link 93 sufficient of itself to complete the engagement of gears 55 and 53, means comprising a bell crank lever 55 and a spring-link 99 are employed. The bellcrank lever 55 is pivoted to the machine-frame at iiiti and carries a downwardly extending abutment 55% which slidably engages a groove it]? formed in the collar of ratchet 5?. As the shaft it is moved to the left by the crowding means previously described, lever 98 is rotated about its pivot 555. The spring link 99 is secured to the lever 95 at I155, and to the machine-frame at When the continued rotation of ratchet 91 has carried pawl 95 to a point where the crowding action of lever 951s nearly spent, the associated movement of bell-crank lever 98 will have flexed spring-link 99 to a point beyond its normal position of repose. The spring reacts to seek a new position of repose, and in so doing swings bell-crank 95 sharply about its pivot, completing the movement of shaft 58 to the left and bringing the gears 5i and 53 into mesh, reversing the ribbon movement. The ribbon will now rewind on left-hand spool 56.

As button 9! moves away from lever 95, spring Hi5 returns lever 95 to its normal position.

The ribbon at the right-hand spool (not shown) is also fitted with a button similar to 9!, and the mechanism consisting of the lever 95, link 53, crowding lever 95 and ratchet 51 is duplicated for the righthand spool. The bellcrank 98 and the spring link 95 will, however, react to complete the throw of shaft 48 in either direction.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewriting machine, the combination with a plurality of pivoted key-levers having wiping-action cams, of a universal bar pivoted to swing at right angles to the direction of movemerit of the key-levers at their cams, the inclination of the cams being at a medial angle with the directions of movement of the keylever and the universal bar, said universal bar having a cushion thereon upon which said key-- lever cams have wiping action, said cams being individually adjustable with respect to said universal bar.

2., In a typewriting machine, the combination with a plurality of pivoted key-levers having 75 wiping-action cams, of a universal bar pivoted to swing at right angles to the direction of movement of the key-levers at their cams, the inclination of the cams being at a medial angle with the directions of movement of the keylever and the universal bar, said universal bar having a buffing pad thereon upon which said key-lever cams have Wiping action, the contacting areas of said cams being extensive so that their pressure upon the pad will be insufficient to solidify the pad.

3. In a typewriting machine, in combination, key-levers, a universal bar pivotally mounted for actuation by impact of the key-levers thereon during the printing stroke of the key-levers, said universal bar moving at substantially right angles to the direction of key-lever travel during the printing-stroke for subduing the noise of contact, and adjustable devices associated with the said key-levers for angular-1y contacting the universal bar and causing it to swing on its pivotal mounting by reason of a wiping contact of said key-lever devices on said universal bar.

4. In a typewriting machine, the combination with a plurality of pivoted key-levers having wiping-action cams, of a universal bar pivoted to swing at right angles to the direction of movement of the key-levers at their cams, the inclination of the cams being at a medial angle with the directions of movement of the key-lever and the universal bar, said universal bar having a buffing pad thereon upon which said key-lever cams have wiping action, said cams being individually adjustable with respect to said universal bar, said key-lever cams being in the form of long, bendable fingers to give an extensive area of contact with the pad and also to afford an adjustment of the universal bar stroke for each finger to secure accuracy of movement.

5. In a typewriting machine, the combination with a plurality of pivoted key-levers having wiping-action cams, of a universal bar pivoted to swing at right angles to the direction of movement of the key-levers at their cams, the inclination of the cams being at a medial angle with the directions of movement of the key-lever and the universal bar, said universal bar having a bufilng pad thereon upon which said key-lever cams have wiping action, said cams being individually adjustable with respect to said universal bar, said key-lever cams being in the form of long, bendable fingers to give an extensive area of contact with the pad and also to afford an adjustment of the universal bar stroke for each finger to secure accuracy of movement, said keylevers pivoted at their rear ends and extending forwardly to the keys and including downwardly bent arms that carry said bendable fingers, the latter extending upwardly and rearwardly from said arms.

6. In a typewriting machine, the combination with a plurality of pivoted key-levers having wiping-action cams, of a universal bar pivoted to swing at right angles to the direction of movement of the key-levers at their cams, the inclination of the cams being at a medial angle with the directions of movement of the key-lever and the universal bar, said universal bar having a bufiing pad thereon upon which said key-lever cams have Wiping action, said cams being individually adjustable with respect to said universal bar, said key-lever cams being in the form of long, bendable fingers to give an extensive area of contact with the pad and also to aiTord an adjustment of the universal bar stroke for each finger to secure accuracy of movement, and thin, yieldable metal fingers forming shields that overlie said pad for resisting the wear of the wiping camfingers and the packing action of the fingers upon the pad.

7. In a typewriting machine, the combination with a plurality of pivoted key-levers having wiping-action cams, of a universal bar pivoted to swing at right angles to the direction of movement of the key-levers at their cams, the inclination of the cams being at a medial angle with the directions of movement of the key-lever and the universal bar, said universal bar having a bufifing pad thereon upon which said key-lever cams have wiping action, said cams being individually adjustable with respect to said universal bar, said key-lever cams being in the form of long, bendable fingers to give an extensive area of contact with the pad and also to afford an adjustment of the universal bar stroke for each finger to secure accuracy of movement, said fingers being formed with lateral flanges on their rear edges to afford enlarged bearing surfaces and reduce pressure bebetween the fingers and the pad at all points.

8. In a typewriting machine, the combination with a plurality of pivoted key-levers having wipingaction cams, of a universal bar pivoted to swing at right angles to the direction of movement of the key-levers at their cams, the inclination of the cams being at a medial angle with the direction of movement of the key-lever and the universal bar, said universal bar having a bufling pad, said cams defining elongate bendable fingers to afford individual adjustment relative to said universal bar, said universal bar including a series of resilient metal tabs, each tab overlying the pad so as to resist wear imparted by the wiping cams and obviate the packing of said pad by contact with the cam fingers.

9. In a typewriting machine, in combination, a universal bar movable in a fore-and-aft direction, and a plurality of key-levers pivoted at their rear ends, each defining a U-shaped contour having an upstanding portion adjacent said universal bar, a cam finger extending obliquely from said upstanding portion and movable therewith in an up-and-down direction to engage said universal bar in a wiping action to quietly actuate same.

10. In a typewriting machine, in combination, a universal bar movable in a fore-and-aft direction, and a plurality of key-levers pivoted at their rear ends, each defining a U-shaped contour having an upstanding portion adjacent said universal bar, a cam finger extending obliquely from said upstanding portion and movable therewith in an up-and-down direction to engage said universal bar in a wiping action to quietly actuate same, said upstanding key-lever portions being ofiset laterally to present a stop for limiting movement of said key-levers.

11. In a typewriting machine, in combination, a universal bar movable in a fore-and-aft direction, and a plurality of key-levers pivoted at their rear ends, each defining a U-shaped contour having an upstanding portion adjacent said universal bar, a cam finger extending obliquely from said upstanding portion and movable therewith in an up-and-down direction to engage said universal bar in a wiping action to quietly actuate same, said universal bar being disposed within the area embraced by the U--shaped portion of said keylevers.

12. In a typewriting machine, the combination with a plurality of key operated members having fingers acting edgewise as elongate wiping-action cams, of a universal bar movable substantially at right angles to the direction of movement of said key members at said cams, a buffing pad on said universal bar presenting a surface engageable by said cams, said cams and bufling pad surface being similarly inclined at a medial angle to the directions of movements of said key members and universal bar so that the contacting area of each I cam on said pad surface is extensive along the cam and the cam impact upon said pad surface is correspondingly distributed to render said impact quiet and to minimize the impact wear on the pad, said fingers being individually bendable to adjust the cams individually relatively to said surface.

WILLIAM A. DOBSON. 

